Perform assays to quantitatively determine the level of SIV or SHIV viral RNA in plasma, mucosal tissue, secretions, lymphoid tissue, or other tissues from nonhuman primates infected with SIV or SHIV Develop new or more sensitive assays to quantitatively detect viral nucleic acids in infected animals, in order to maintain the capability of providing state-of- the-art assays under this contract. Improve current assays as needed to meet the scope of work.